Photo theme of the week 8/4 - 8/11:Motion

[Drayven]

Reaching into the big bag of theme ideas I hereby decree this week be the week of motion. The theme of the week is 'Motion'

[Wackman3000]

This one's easy for me, because the thing that puts me in motion is also the thing that I routinely snap pictures of, and I did so just this weekend:





I've always wanted to attempt a shot of my car while rolling though, but I have no idea how to do it, nor had someone with a decent camera to do it... I use my dad's Canon G10... Would it even be possible to take a shot like this with it?

[Drayven]

I took this one the other night when i was testing the night landscape mode on my camera. A car was coming by so I quickly setup to capture it.

[KillerMcDead]

Originally Posted by Wackman3000

I've always wanted to attempt a shot of my car while rolling though, but I have no idea how to do it, nor had someone with a decent camera to do it... I use my dad's Canon G10... Would it even be possible to take a shot like this with it?

Now I could be wrong, seeing as how I'm just learning these things myself, but for a picture like that you would probably want to open up your Aperture and set a faster shutter speed.

As I understand, opening up your aperture to let more light in will bring objects in the foreground into focus while blurring the background. Then a fast shutter speed so the car itself doesn't come out blurry. Again, I could be wrong, I just bought my first camera about a week ago and I'm slowly reading up/just figuring things out for myself. If somebody wants to correct me, please do.

[wyeast]

Playing with the aperture does shorten the focal length, but the deep background is in focus while the near background is not. That's motion blur, rather than static. Smaller aperture, longer shutter time.

You want to either be pacing in another car or learn to track movement (i.e. camera follows the car as it passes) Position and the amount of blur on the nearby trees leads me to think this was done by pacing.

Tracking lends itself more to side-on shots where you follow the car with the camera. I don't have any car examples offhand, but here's one with a bike (albiet, in low light so it's pretty crummy anyway, but you get the idea...)

[KillerMcDead]

How it was explained to me was, when the aperture is smaller, all light entering the lens comes through at a straight angle, keeping everything in focus. When the aperture is open, it allows more light to enter the lens, but the light around the outside of the picture bends to get in. That's the best I'm able to explain it. Here's a quote from wikipedia:

In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are, which is of great importance for the appearance at the image plane. If an aperture is narrow, then highly collimated rays are admitted, resulting in a sharp focus at the image plane. If an aperture is wide, then uncollimated rays are admitted, resulting in a sharp focus only for rays with a certain focal length.

Again, my understanding of this could be wrong, but while playing with my camera's aperture, I was able to take photos like these:

[wyeast]

This is true. However in the particular car shot, the road immediately around the car is very blurry, while the trees in the far back (right side) is relatively in focus. With a wide aperture shot, the opposite would be true. In this case, the level of blur is proportional to the speed relative to a camera positioned in a car running alongside. The body of the car is in focus, but the road and wheels are totally blurred out.

Blur in the back is minimal, while nearer to the car, it's linear with the direction of travel.

All classic signs of a moving camera following the car.

With a stationary camera tracking the car, the far background would be more blurred than the road up close.

With a stationary camera with wide aperture/fast shutter, the immediate surroundings by the car would be in focus, blur increasing with distance. In your example, the grolsch bottle is almost in focus because it's near the jack, but the picture in the background is blotto.

Interestingly, with many point and shoot cameras, the wide aperture trick is hard to pull off because the small sensor limits your ability. Up close in macro, yeah. But focusing on something more than a few feet out and pretty much everything is in focus (relatively)

[KillerMcDead]

Sorry yeah I went off on a bit of a tangent and stopped talking about the picture in question. My bad.

[Jackel]

Wyeast is right. We actually talked about this in irc today as I gave Wackman a few tips on how to take one himself. I'd write more about it but I've got visitors.

[wyeast]

Originally Posted by Jackel

I'd write more about it but I've got visitors.

Dude, those guys are lizards!

Originally Posted by KillerMcDead

Sorry yeah I went off on a bit of a tangent and stopped talking about the picture in question. My bad.

*shakes fist*

[Kielaran]

I heard that playing with your aperture will make you go blind.

I have nothing useful to add here.